Avaliação de dentifrício com concentração reduzida de fluoreto associado ao glicerofosfato de cálcio na desmineralização do esmalte dentário in situ

O uso do fluoreto tem sido considerado um importante fator na redução da incidência da cárie dentária, porém tem-se verificado um aumento da fluorose dentária quando associado ao uso deste elemento. O objetivo deste estudo foi verificar o efeito de um dentifrício com concentração reduzida de fluoreto suplementado com glicerofosfato de cálcio (GPCa) em inibir o processo de desmineralização e sobre a placa dental formada in situ. Voluntários (n=10) participaram de 4 fases experimentais de 7 dias de duração cada, em cada fase utilizaram um dispositivo palatino contendo 4 blocos de esmalte dental bovino. O desafio cariogênico foi realizado por meio de solução de sacarose 30%, 6 vezes ao dia. Os dentifrícios utilizados neste estudo foram: placebo, 500 μg F/g, 500 μg F/g com 0,25% de GPCa e 1100 μg F/g. Decorrido o período experimental, a placa dental foi coletada, processada, a concentração iônica (fluoreto, cálcio e fosfato) e de polissacarídeos extracelulares (PEC) determinadas. Analisou-se a dureza de superfície inicial e final e em secção longitudinal. Determinou-se a concentração de fluoreto, cálcio e fosfato no esmalte. O uso de dentifrícios contendo 1100 μg F/g e 500 μg F/g com 0,25% de GPCa levou a concentrações semelhantes de fluoreto, cálcio e fosfato na placa, as quais foram maiores que as obtidas após o uso dos demais dentifrícios. A concentração de PEC e a perda mineral foram menores nos dentifrícios 1100 μg F/g e 500 μg F/g com 0,25% de GPCa, seguido pelo 500 μg F/g e placebo, o qual apresentou os menores valores. As concentrações de fluoreto, cálcio e fosfato no esmalte foram menores no grupo placebo, sendo os maiores valores encontrados nos grupos 500 μg F/g com 0,25% de GPCa e 1100 μg F/g (p<0,05). De acordo com os resultados o dentifrício com baixa concentração associado ao GPCa, apresentou resultado semelhante ao...The use of fluoride has been considered as an important factor for decrease in the incidence of dental caries, however dental fluorosis increase associated with the use of this element. This in situ study aims to evaluate the effect of low fluoride concentration dentifrices supplemented with calcium glycerophosphate (CaGP) in inhibiting the demineralization process and on the dental plaque formed in situ. Ten volunteers wore palatal devices containing 4 blocks of bovine dental enamel over 3 periods of 7 days each. In each phase, treatment was accomplished with a nonfluoride dentifrice (placebo), a 500 μg F/g, a 500 μg F/g with 0.25% CaGP and a 1,100 μg F/g dentifrice, under cariogenic challenge with 30% sucrose solution 6 times a day. After that, the dental plaque was collected and processed, and the ionic (fluoride, calcium, and phosphate) and insoluble extracellular polysaccharide (EPS) concentrations were appraised. To evaluate mineral loss, we determined both the initial and final surface hardness and cross-sectional hardness (ΔKHN). The fluoride, calcium, and phosphate concentration in the enamel were determined. The use of dentifrices containing 1100 μg F/g and 500 μg F/g with 0.25% CaGP led to similar concentrations of fluoride, calcium and phosphate in dental plaque, but higher than those obtained after the use of the placebo and 500 μg F/g dentifrices . The concentration of EPS and mineral loss was lower in 500 μg F/g with 0.25% of CaGP e 1,100 μg F/g. The concentration of fluoride, calcium, and phosphate in enamel was higher in groups 500 μg F/g with 0.25% of CaGP e 1,100 μg F/g (p <0.05). It was concluded that the low fluoride concentration dentifrice with 0.25% CaGP, showed similar efficacy to the positive control (1,100 μg F / g) in demineralization in situ, could be an alternative to improve the risk-benefit relationship between fluorosis and dental cariesCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Effect of sodium trimetaphosphate on hydroxyapatite solubility: An in vitro study

This study evaluated the effect of different concentrations of sodium trimetaphosphate (TMP) with and without fluoride (F) on the concentration of calcium (Ca), phosphorus (P) and F in hydroxyapatite (HA). Synthetic HA powder (0.15 g) was suspended (n=6) in solutions (75 mL) of TMP at 0%, 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 2.0%, 4.0%, 6.0%, 8.0% and 10% concentrations in the presence and absence of 100 ppm F and subjected to a pH-cycling process. The precipitates were filtrated, dried at 70° C for 24 h and ground onto a fine powder. The concentrations of F (KOH (CaF2) and HCl (FA) soluble), Ca (Arsenazo III), and P (molybdate method) in HA were determined. The Ca P, and Ca/P ratio data were subjected to Tukey's test and the F data were subjected to Student-Newman-Keuls test (p<0.05). The addition of TMP to the samples reduced F deposition to 98% (p<0.001). The groups containing 100 ppm F and 0.4% or 0.6% TMP exhibited a higher Ca concentration than the group containing only 100 ppm F (p<0.05). Furthermore, the HA treated with 0.2% and 0.4% TMP and 100 ppm F showed a higher Ca/P ratio than the other groups (p<0.001). In conclusion, TMP at 0.2%, 0.4% and 0.6% concentrations combined with F seemed to be able to precipitate HA with low solubility. However, especially at high concentrations, TMP interferes with F deposition on HA

Nanosynthesis of Silver-Calcium Glycerophosphate: Promising Association against Oral Pathogens

Nanobiomaterials combining remineralization and antimicrobial abilities would bring important benefits to control dental caries. This study aimed to produce nanocompounds containing calcium glycerophosphate (CaGP) and silver nanoparticles (AgNP) by varying the reducing agent of silver nitrate (sodium borohydride (B) or sodium citrate (C)), the concentration of silver (1% or 10%), and the CaGP forms (nano or commercial), and analyze its characterization and antimicrobial activity against ATCC Candida albicans (10231) and Streptococcus mutans (25175) by the microdilution method. Controls of AgNP were produced and silver ions (Ag+) were quantified in all of the samples. X-ray diffraction, UV-Vis, and scanning electron microscopy (SEM) analysis demonstrated AgNP associated with CaGP. Ag+ ions were considerably higher in AgCaGP/C. C. albicans was susceptible to nanocompounds produced with both reducing agents, regardless of Ag concentration and CaGP form, being Ag10%CaGP-N/C the most effective compound (19.5&ndash;39.0 &micro;g Ag mL&minus;1). While for S. mutans, the effectiveness was observed only for AgCaGP reduced by citrate, also presenting Ag10%CaGP-N the highest effectiveness (156.2&ndash;312.5 &micro;g Ag mL&minus;1). Notably, CaGP enhanced the silver antimicrobial potential in about two- and eight-fold against C. albicans and S. mutans when compared with the AgNP controls (from 7.8 to 3.9 and from 250 to 31.2 &micro;g Ag mL&minus;1, respectively). The synthesis that was used in this study promoted the formation of AgNP associated with CaGP, and although the use of sodium borohydride (B) resulted in a pronounced reduction of Ag+, the composite AgCaGP/B was less effective against the microorganisms that were tested